Summarize-then-Answer: Generating Concise Explanations for Multi-hop Reading Comprehension

Naoya Inoue, Harsh Trivedi, Steven Sinha, Niranjan Balasubramanian, Kentaro Inui


Abstract
How can we generate concise explanations for multi-hop Reading Comprehension (RC)? The current strategies of identifying supporting sentences can be seen as an extractive question-focused summarization of the input text. However, these extractive explanations are not necessarily concise i.e. not minimally sufficient for answering a question. Instead, we advocate for an abstractive approach, where we propose to generate a question-focused, abstractive summary of input paragraphs and then feed it to an RC system. Given a limited amount of human-annotated abstractive explanations, we train the abstractive explainer in a semi-supervised manner, where we start from the supervised model and then train it further through trial and error maximizing a conciseness-promoted reward function. Our experiments demonstrate that the proposed abstractive explainer can generate more compact explanations than an extractive explainer with limited supervision (only 2k instances) while maintaining sufficiency.
Anthology ID:
2021.emnlp-main.490
Volume:
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2021
Address:
Online and Punta Cana, Dominican Republic
Editors:
Marie-Francine Moens, Xuanjing Huang, Lucia Specia, Scott Wen-tau Yih
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6064–6080
Language:
URL:
https://aclanthology.org/2021.emnlp-main.490
DOI:
10.18653/v1/2021.emnlp-main.490
Bibkey:
Cite (ACL):
Naoya Inoue, Harsh Trivedi, Steven Sinha, Niranjan Balasubramanian, and Kentaro Inui. 2021. Summarize-then-Answer: Generating Concise Explanations for Multi-hop Reading Comprehension. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing, pages 6064–6080, Online and Punta Cana, Dominican Republic. Association for Computational Linguistics.
Cite (Informal):
Summarize-then-Answer: Generating Concise Explanations for Multi-hop Reading Comprehension (Inoue et al., EMNLP 2021)
Copy Citation:
PDF:
https://preview.aclanthology.org/nschneid-patch-2/2021.emnlp-main.490.pdf
Video:
 https://preview.aclanthology.org/nschneid-patch-2/2021.emnlp-main.490.mp4
Code
 stonybrooknlp/suqa
Data
CoLAHotpotQA